diff --git a/res/layout-land/main.xml b/res/layout-land/main.xml
index ad76b96a..114fbc00 100644
--- a/res/layout-land/main.xml
+++ b/res/layout-land/main.xml
@@ -13,183 +13,76 @@
 			a:orientation="vertical"
 			a:layout_gravity="center">
 
-		<LinearLayout a:layout_weight="2" a:layout_width="match_parent" a:layout_height="0dp">
-
-			<org.solovyev.android.calculator.CalculatorEditor
-					a:id="@+id/editText"
-					style="@style/display_style"
-					a:inputType="textMultiLine"
-					a:singleLine="false"/>
-
-		</LinearLayout>
+		<include layout="@layout/calc_editor"/>
 
 		<LinearLayout a:layout_weight="1" a:layout_width="match_parent" a:layout_height="0dp">
 
 			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/leftButton"
-														   calc:textUp="↞"
-														   a:text="←"
-														   a:layout_weight="1.5"
-														   style="@style/control_button_style"
-														   a:onClick="moveLeftButtonClickHandler"/>
+																   calc:textUp="↞"
+																   a:text="←"
+																   a:layout_weight="1.5"
+																   style="@style/control_button_style"
+																   a:onClick="moveLeftButtonClickHandler"/>
 
 			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/eraseButton"
-														   a:text="↚"
-														   a:layout_weight="1.5"
-														   style="@style/control_button_style"
-														   a:onClick="eraseButtonClickHandler"/>
+																   a:text="@string/c_erase"
+																   a:layout_weight="1.5"
+																   style="@style/control_button_style"
+																   a:onClick="eraseButtonClickHandler"/>
+
+			<include layout="@layout/calc_display"/>
 
-			<org.solovyev.android.calculator.CalculatorDisplay
-					a:id="@+id/resultEditText"
-					style="@style/display_style"
-					a:gravity="right|top"
-					a:layout_weight="1"
-					a:minLines="1"
-					a:maxLines="1"
-					a:textStyle="bold"
-					a:scrollHorizontally="true"
-					a:scrollbars="none"/>
 
 			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/clearButton"
-														   a:text="@string/c_clear"
-														   a:layout_weight="1.5"
-														   style="@style/control_button_style"
-														   a:onClick="clearButtonClickHandler"/>
+																   a:text="@string/c_clear"
+																   a:layout_weight="1.5"
+																   style="@style/control_button_style"
+																   a:onClick="clearButtonClickHandler"/>
 
 			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/rightButton"
-														   calc:textUp="↠"
-														   a:text="→"
-														   a:layout_weight="1.5"
-														   style="@style/control_button_style"
-														   a:onClick="moveRightButtonClickHandler"/>
+																   calc:textUp="↠"
+																   a:text="→"
+																   a:layout_weight="1.5"
+																   style="@style/control_button_style"
+																   a:onClick="moveRightButtonClickHandler"/>
 
 
 		</LinearLayout>
 
 		<LinearLayout a:layout_weight="1" a:layout_width="match_parent" a:layout_height="0dp">
 
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/oneDigitButton"
-																   a:text="1"
-																   calc:textUp="sin"
-														   			calc:textDown="asin"
-																	style="@style/digit_button_style"
-														   			a:onClick="digitButtonClickHandler"/>
+			<include layout="@layout/calc_one_digit_button"/>
+			<include layout="@layout/calc_two_digit_button"/>
+			<include layout="@layout/calc_three_digit_button"/>
+			<include layout="@layout/calc_multiplication_button"/>
+			<include layout="@layout/calc_division_button"/>
+			<include layout="@layout/calc_equals_button"/>
+			<include layout="@layout/calc_paste_button"/>
 
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/twoDigitButton"
-																   a:text="2"
-																   calc:textUp="cos"
-														   			calc:textDown="acos" style="@style/digit_button_style"
-														   a:onClick="digitButtonClickHandler"/>
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/threeDigitButton" a:text="3" calc:textUp="tan"
-														   calc:textDown="atan" style="@style/digit_button_style"
-														   a:onClick="digitButtonClickHandler"/>
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/multiplicationButton" a:text="×"
-														   calc:textUp="^"
-														   calc:textDown="^2" style="@style/digit_button_style"
-														   a:onClick="digitButtonClickHandler"/>
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/divisionButton" a:text="/"
-														   calc:textUp="√"
-														   style="@style/digit_button_style"
-														   a:onClick="digitButtonClickHandler"/>
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/equalsButton"
-														   a:text="="
-														   a:layout_width="fill_parent"
-														   style="@style/control_button_style"
-														   a:onClick="numericButtonClickHandler"/>
-
-			<ImageButton a:id="@+id/pasteButton"
-						 a:src="@drawable/paste"
-						 style="@style/control_button_style"
-						 a:onClick="pasteButtonClickHandler"/>
 
 		</LinearLayout>
 
 		<LinearLayout a:layout_weight="1" a:layout_width="match_parent" a:layout_height="0dp">
 
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/fourDigitButton"
-														   a:text="4"
-														   calc:textUp="sinh"
-														   calc:textDown="asinh"
-														   style="@style/digit_button_style"
-														   a:onClick="digitButtonClickHandler"/>
+			<include layout="@layout/calc_four_digit_button"/>
+			<include layout="@layout/calc_five_digit_button"/>
+			<include layout="@layout/calc_six_digit_button"/>
+			<include layout="@layout/calc_plus_button"/>
+			<include layout="@layout/calc_subtraction_button"/>
+			<include layout="@layout/calc_square_brackets_button"/>
+			<include layout="@layout/calc_history_button"/>
 
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/fiveDigitButton"
-														   a:text="5"
-														   calc:textUp="cosh"
-														   calc:textDown="acosh"
-														   style="@style/digit_button_style"
-														   a:onClick="digitButtonClickHandler"/>
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/sixDigitButton" a:text="6"
-														   calc:textUp="tanh"
-														   calc:textDown="atanh"
-														   style="@style/digit_button_style"
-														   a:onClick="digitButtonClickHandler"/>
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/plusButton" a:text="+"
-														   style="@style/digit_button_style"
-														   a:onClick="digitButtonClickHandler"/>
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/minusButton" a:text="-"
-														   calc:textUp="{"
-														   calc:textDown="}"
-														   style="@style/digit_button_style"
-														   a:onClick="digitButtonClickHandler"/>
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/squareBracketsButton" a:text="[]"
-														   calc:textUp="["
-														   calc:textDown="]" style="@style/digit_button_style"
-														   a:onClick="digitButtonClickHandler"/>
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/historyButton"
-														   a:text=""
-														   calc:textUp="@string/c_undo"
-														   calc:textDown="@string/c_redo"
-														   style="@style/control_button_style"/>
 
 		</LinearLayout>
 
 		<LinearLayout a:layout_weight="1" a:layout_width="match_parent" a:layout_height="0dp">
 
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/sevenDigitButton" a:text="7"
-														   calc:textUp="i"
-														   calc:textDown=""
-														   style="@style/digit_button_style"
-														   a:onClick="digitButtonClickHandler"/>
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/eightDigitButton" a:text="8"
-														   calc:textUp="ln"
-														   calc:textDown=""
-														   style="@style/digit_button_style"
-														   a:onClick="digitButtonClickHandler"/>
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/nineDigitButton" a:text="9"
-														   calc:textDown="e"
-														   calc:textUp="π"
-														   style="@style/digit_button_style"
-														   a:onClick="digitButtonClickHandler"/>
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/zeroDigitButton" a:text="0"
-														   calc:textUp="."
-														   calc:textDown=","
-														   style="@style/digit_button_style"
-														   a:onClick="digitButtonClickHandler"/>
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/roundBracketsButton" a:text="()"
-														   calc:textUp="("
-														   calc:textDown=")" style="@style/digit_button_style"
-														   a:onClick="digitButtonClickHandler"/>
-
-			<org.solovyev.android.view.widgets.DirectionDragButton
-					a:id="@+id/varsButton"
-					a:text="π,e,…"
-					a:textStyle="italic"
-					a:onClick="varsButtonClickHandler"
-					style="@style/control_button_style"/>
-
+			<include layout="@layout/calc_seven_digit_button"/>
+			<include layout="@layout/calc_eight_digit_button"/>
+			<include layout="@layout/calc_nine_digit_button"/>
+			<include layout="@layout/calc_zero_digit_button"/>
+			<include layout="@layout/calc_round_brackets_button"/>
+			<include layout="@layout/calc_vars_button"/>
 			<org.solovyev.android.view.widgets.DirectionDragButton a:text="" style="@style/control_button_style"/>
 
 
diff --git a/res/layout-port/main.xml b/res/layout-port/main.xml
index 8c1eb2bc..de58d175 100644
--- a/res/layout-port/main.xml
+++ b/res/layout-port/main.xml
@@ -1,7 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 
 <LinearLayout xmlns:a="http://schemas.android.com/apk/res/android"
-			  xmlns:calc="http://schemas.android.com/apk/res/org.solovyev.android.calculator"
 			  a:orientation="vertical"
 			  a:layout_width="match_parent"
 			  a:layout_height="match_parent"
@@ -13,195 +12,69 @@
 			a:orientation="vertical"
 			a:layout_gravity="center">
 
-		<LinearLayout a:layout_weight="2" a:layout_width="match_parent" a:layout_height="0dp">
-
-			<org.solovyev.android.calculator.CalculatorEditor
-					a:id="@+id/editText"
-					style="@style/display_style"
-					a:inputType="textMultiLine"
-					a:singleLine="false"/>
-
-		</LinearLayout>
-
-		<LinearLayout a:layout_weight="1" a:layout_width="match_parent" a:layout_height="0dp">
-
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/equalsButton"
-																   a:text="="
-																   a:layout_width="fill_parent"
-																   a:layout_weight="4"
-																   style="@style/control_button_style"
-																   a:onClick="numericButtonClickHandler"/>
-
-			<org.solovyev.android.calculator.CalculatorDisplay
-					a:id="@+id/resultEditText"
-					style="@style/display_style"
-					a:gravity="right|top"
-					a:layout_weight="1"
-					a:minLines="1"
-					a:maxLines="1"
-					a:textStyle="bold"
-					a:scrollHorizontally="true"
-					a:scrollbars="none"/>
-
-		</LinearLayout>
-
-		<LinearLayout a:layout_weight="1" a:layout_width="match_parent" a:layout_height="0dp">
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/oneDigitButton" a:text="1" calc:textUp="sin"
-																   calc:textDown="asin" style="@style/digit_button_style"
-																   a:onClick="digitButtonClickHandler"/>
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/twoDigitButton" a:text="2" calc:textUp="cos"
-																   calc:textDown="acos" style="@style/digit_button_style"
-																   a:onClick="digitButtonClickHandler"/>
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/threeDigitButton" a:text="3" calc:textUp="tan"
-																   calc:textDown="atan" style="@style/digit_button_style"
-																   a:onClick="digitButtonClickHandler"/>
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/multiplicationButton" a:text="×"
-																   calc:textUp="^"
-																   calc:textDown="^2" style="@style/digit_button_style"
-																   a:onClick="digitButtonClickHandler"/>
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/clearButton"
-																   a:text="@string/c_clear"
-																   style="@style/control_button_style"
-																   a:onClick="clearButtonClickHandler"/>
-
-		</LinearLayout>
-
-		<LinearLayout a:layout_weight="1" a:layout_width="match_parent" a:layout_height="0dp">
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/fourDigitButton"
-																   a:text="4"
-																   calc:textUp="sinh"
-																   calc:textDown="asinh"
-																   style="@style/digit_button_style"
-																   a:onClick="digitButtonClickHandler"/>
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/fiveDigitButton"
-																   a:text="5"
-																   calc:textUp="cosh"
-																   calc:textDown="acosh"
-																   style="@style/digit_button_style"
-																   a:onClick="digitButtonClickHandler"/>
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/sixDigitButton" a:text="6"
-																   calc:textUp="tanh"
-																   calc:textDown="atanh"
-																   style="@style/digit_button_style"
-																   a:onClick="digitButtonClickHandler"/>
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/divisionButton" a:text="/"
-																   calc:textUp="√"
-																   style="@style/digit_button_style"
-																   a:onClick="digitButtonClickHandler"/>
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/eraseButton"
-																   a:text="↚"
-																   style="@style/control_button_style"
-																   a:onClick="eraseButtonClickHandler"/>
-
-		</LinearLayout>
-
-		<LinearLayout a:layout_weight="1" a:layout_width="match_parent" a:layout_height="0dp">
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/sevenDigitButton" a:text="7"
-																   calc:textUp="i"
-																   calc:textDown=""
-																   style="@style/digit_button_style"
-																   a:onClick="digitButtonClickHandler"/>
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/eightDigitButton" a:text="8"
-																   calc:textUp="ln"
-																   calc:textDown=""
-																   style="@style/digit_button_style"
-																   a:onClick="digitButtonClickHandler"/>
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/nineDigitButton" a:text="9"
-																   calc:textDown="e"
-																   calc:textUp="π"
-																   style="@style/digit_button_style"
-																   a:onClick="digitButtonClickHandler"/>
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/plusButton" a:text="+"
-																   style="@style/digit_button_style"
-																   a:onClick="digitButtonClickHandler"/>
-
-			<ImageButton a:id="@+id/pasteButton"
-						 a:src="@drawable/paste"
-						 style="@style/control_button_style"
-						 a:onClick="pasteButtonClickHandler"/>
-
-
-		</LinearLayout>
-
-		<LinearLayout a:layout_weight="1" a:layout_width="match_parent" a:layout_height="0dp">
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/roundBracketsButton" a:text="()"
-																   calc:textUp="("
-																   calc:textDown=")" style="@style/digit_button_style"
-																   a:onClick="digitButtonClickHandler"/>
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/zeroDigitButton" a:text="0"
-																   calc:textUp="."
-																   calc:textDown=","
-																   style="@style/digit_button_style"
-																   a:onClick="digitButtonClickHandler"/>
-
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/squareBracketsButton" a:text="[]"
-																   calc:textUp="["
-																   calc:textDown="]" style="@style/digit_button_style"
-																   a:onClick="digitButtonClickHandler"/>
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/subtractionButton" a:text="-"
-																   calc:textUp="{"
-																   calc:textDown="}"
-																   style="@style/digit_button_style"
-																   a:onClick="digitButtonClickHandler"/>
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/historyButton"
-																   a:text=""
-																   calc:textUp="@string/c_undo"
-																   calc:textDown="@string/c_redo"
-																   style="@style/control_button_style"/>
-
-		</LinearLayout>
+		<include layout="@layout/calc_editor"/>
 
 
 		<LinearLayout a:layout_weight="1" a:layout_width="match_parent" a:layout_height="0dp">
 
-
-			<!--				<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/numericButton" a:text="numeric"
-																									   style="@style/digit_button_style"
-																									   a:onClick="numericButtonClickHandler"/>
-
-														<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/simplifyButton" a:text="simplify"
-																									   style="@style/digit_button_style"
-																									   a:onClick="simplifyButtonClickHandler"/>-->
-
-			<org.solovyev.android.view.widgets.DirectionDragButton a:id="@+id/leftButton"
-																   calc:textUp="↞"
-																   a:text="←"
-																   style="@style/control_button_style"
-																   a:onClick="moveLeftButtonClickHandler"/>
-
 			<org.solovyev.android.view.widgets.DirectionDragButton
-					a:id="@+id/rightButton"
-					calc:textUp="↠"
-					a:text="→"
+					xmlns:a="http://schemas.android.com/apk/res/android"
+					a:id="@+id/equalsButton"
+					a:text="="
+					a:layout_weight="4"
 					style="@style/control_button_style"
-					a:onClick="moveRightButtonClickHandler"/>
+					a:onClick="numericButtonClickHandler"/>
 
-			<org.solovyev.android.view.widgets.DirectionDragButton
-					a:id="@+id/varsButton"
-					a:text="π,e,…"
-					a:textStyle="italic"
-					a:onClick="varsButtonClickHandler"
-					style="@style/control_button_style"/>
+			<include layout="@layout/calc_display"/>
+
+		</LinearLayout>
+
+		<LinearLayout a:layout_weight="1" a:layout_width="match_parent" a:layout_height="0dp">
+
+			<include layout="@layout/calc_one_digit_button"/>
+			<include layout="@layout/calc_two_digit_button"/>
+			<include layout="@layout/calc_three_digit_button"/>
+			<include layout="@layout/calc_multiplication_button"/>
+			<include layout="@layout/calc_clear_button"/>
+
+		</LinearLayout>
+
+		<LinearLayout a:layout_weight="1" a:layout_width="match_parent" a:layout_height="0dp">
+
+			<include layout="@layout/calc_four_digit_button"/>
+			<include layout="@layout/calc_five_digit_button"/>
+			<include layout="@layout/calc_six_digit_button"/>
+			<include layout="@layout/calc_division_button"/>
+			<include layout="@layout/calc_erase_button"/>
+
+		</LinearLayout>
+
+		<LinearLayout a:layout_weight="1" a:layout_width="match_parent" a:layout_height="0dp">
+
+			<include layout="@layout/calc_seven_digit_button"/>
+			<include layout="@layout/calc_eight_digit_button"/>
+			<include layout="@layout/calc_nine_digit_button"/>
+			<include layout="@layout/calc_plus_button"/>
+			<include layout="@layout/calc_paste_button"/>
+
+		</LinearLayout>
+
+		<LinearLayout a:layout_weight="1" a:layout_width="match_parent" a:layout_height="0dp">
+
+			<include layout="@layout/calc_round_brackets_button"/>
+			<include layout="@layout/calc_zero_digit_button"/>
+			<include layout="@layout/calc_square_brackets_button"/>
+			<include layout="@layout/calc_subtraction_button"/>
+			<include layout="@layout/calc_history_button"/>
+
+		</LinearLayout>
+
+
+		<LinearLayout a:layout_weight="1" a:layout_width="match_parent" a:layout_height="0dp">
+
+			<include layout="@layout/calc_left_button"/>
+			<include layout="@layout/calc_right_button"/>
+			<include layout="@layout/calc_vars_button"/>
 
 			<org.solovyev.android.view.widgets.DirectionDragButton a:text="" style="@style/control_button_style"/>
 
diff --git a/res/layout/calc_clear_button.xml b/res/layout/calc_clear_button.xml
new file mode 100644
index 00000000..b23a7d5a
--- /dev/null
+++ b/res/layout/calc_clear_button.xml
@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+  ~ For more information, please, contact se.solovyev@gmail.com
+  ~ or visit http://se.solovyev.org
+  -->
+
+<org.solovyev.android.view.widgets.DirectionDragButton xmlns:a="http://schemas.android.com/apk/res/android"
+													   xmlns:calc="http://schemas.android.com/apk/res/org.solovyev.android.calculator"
+													   a:id="@+id/clearButton"
+													   a:text="@string/c_clear"
+													   style="@style/control_button_style"
+													   a:onClick="clearButtonClickHandler"/>
\ No newline at end of file
diff --git a/res/layout/calc_display.xml b/res/layout/calc_display.xml
new file mode 100644
index 00000000..4cd8b0ed
--- /dev/null
+++ b/res/layout/calc_display.xml
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+  ~ For more information, please, contact se.solovyev@gmail.com
+  ~ or visit http://se.solovyev.org
+  -->
+
+<org.solovyev.android.calculator.CalculatorDisplay
+		xmlns:a="http://schemas.android.com/apk/res/android"
+		a:id="@+id/resultEditText"
+		style="@style/display_style"
+		a:layout_weight="1"
+		a:minLines="1"
+		a:maxLines="1"
+		a:textStyle="bold"
+		a:scrollHorizontally="true"
+		a:scrollbars="none"/>
\ No newline at end of file
diff --git a/res/layout/calc_division_button.xml b/res/layout/calc_division_button.xml
new file mode 100644
index 00000000..af34e07e
--- /dev/null
+++ b/res/layout/calc_division_button.xml
@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+  ~ For more information, please, contact se.solovyev@gmail.com
+  ~ or visit http://se.solovyev.org
+  -->
+
+<org.solovyev.android.view.widgets.DirectionDragButton xmlns:a="http://schemas.android.com/apk/res/android"
+													   xmlns:calc="http://schemas.android.com/apk/res/org.solovyev.android.calculator"
+													   a:id="@+id/divisionButton" a:text="/"
+													   calc:textUp="√"
+													   style="@style/digit_button_style"
+													   a:onClick="digitButtonClickHandler"/>
\ No newline at end of file
diff --git a/res/layout/calc_editor.xml b/res/layout/calc_editor.xml
new file mode 100644
index 00000000..96b36dea
--- /dev/null
+++ b/res/layout/calc_editor.xml
@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+  ~ For more information, please, contact se.solovyev@gmail.com
+  ~ or visit http://se.solovyev.org
+  -->
+
+<LinearLayout xmlns:a="http://schemas.android.com/apk/res/android"
+			  a:layout_weight="2"
+			  a:layout_width="match_parent"
+			  a:layout_height="0dp">
+
+	<org.solovyev.android.calculator.CalculatorEditor
+			a:id="@+id/editText"
+			style="@style/editor_style"
+			a:inputType="textMultiLine"
+			a:maxLines="4"
+			a:scrollbars="vertical"
+			a:hint ="@string/c_calc_editor_hint"/>
+
+</LinearLayout>
\ No newline at end of file
diff --git a/res/layout/calc_eight_digit_button.xml b/res/layout/calc_eight_digit_button.xml
new file mode 100644
index 00000000..8f3a85c1
--- /dev/null
+++ b/res/layout/calc_eight_digit_button.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+  ~ For more information, please, contact se.solovyev@gmail.com
+  ~ or visit http://se.solovyev.org
+  -->
+
+<org.solovyev.android.view.widgets.DirectionDragButton xmlns:a="http://schemas.android.com/apk/res/android"
+													   xmlns:calc="http://schemas.android.com/apk/res/org.solovyev.android.calculator"
+													   a:id="@+id/eightDigitButton" a:text="8"
+													   calc:textUp="ln"
+													   calc:textDown=""
+													   style="@style/digit_button_style"
+													   a:onClick="digitButtonClickHandler"/>
\ No newline at end of file
diff --git a/res/layout/calc_equals_button.xml b/res/layout/calc_equals_button.xml
new file mode 100644
index 00000000..11a5eb96
--- /dev/null
+++ b/res/layout/calc_equals_button.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+  ~ For more information, please, contact se.solovyev@gmail.com
+  ~ or visit http://se.solovyev.org
+  -->
+<org.solovyev.android.view.widgets.DirectionDragButton
+		xmlns:a="http://schemas.android.com/apk/res/android"
+		a:id="@+id/equalsButton"
+		a:text="="
+		a:layout_width="match_parent"
+		a:layout_height="match_parent"
+		style="@style/control_button_style"
+		a:onClick="numericButtonClickHandler"/>
\ No newline at end of file
diff --git a/res/layout/calc_erase_button.xml b/res/layout/calc_erase_button.xml
new file mode 100644
index 00000000..13d49758
--- /dev/null
+++ b/res/layout/calc_erase_button.xml
@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+  ~ For more information, please, contact se.solovyev@gmail.com
+  ~ or visit http://se.solovyev.org
+  -->
+
+<org.solovyev.android.view.widgets.DirectionDragButton xmlns:a="http://schemas.android.com/apk/res/android"
+													   xmlns:calc="http://schemas.android.com/apk/res/org.solovyev.android.calculator"
+													   a:id="@+id/eraseButton"
+													   a:text="@string/c_erase"
+													   style="@style/control_button_style"
+													   a:onClick="eraseButtonClickHandler"/>
\ No newline at end of file
diff --git a/res/layout/calc_five_digit_button.xml b/res/layout/calc_five_digit_button.xml
new file mode 100644
index 00000000..e0298ed0
--- /dev/null
+++ b/res/layout/calc_five_digit_button.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+  ~ For more information, please, contact se.solovyev@gmail.com
+  ~ or visit http://se.solovyev.org
+  -->
+<org.solovyev.android.view.widgets.DirectionDragButton xmlns:a="http://schemas.android.com/apk/res/android"
+													   xmlns:calc="http://schemas.android.com/apk/res/org.solovyev.android.calculator"
+													   a:id="@+id/fiveDigitButton"
+													   a:text="5"
+													   calc:textUp="cosh"
+													   calc:textDown="acosh"
+													   style="@style/digit_button_style"
+													   a:onClick="digitButtonClickHandler"/>
\ No newline at end of file
diff --git a/res/layout/calc_four_digit_button.xml b/res/layout/calc_four_digit_button.xml
new file mode 100644
index 00000000..0e91a73d
--- /dev/null
+++ b/res/layout/calc_four_digit_button.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+  ~ For more information, please, contact se.solovyev@gmail.com
+  ~ or visit http://se.solovyev.org
+  -->
+<org.solovyev.android.view.widgets.DirectionDragButton xmlns:a="http://schemas.android.com/apk/res/android"
+													   xmlns:calc="http://schemas.android.com/apk/res/org.solovyev.android.calculator"
+													   a:id="@+id/fourDigitButton"
+													   a:text="4"
+													   calc:textUp="sinh"
+													   calc:textDown="asinh"
+													   style="@style/digit_button_style"
+													   a:onClick="digitButtonClickHandler"/>
\ No newline at end of file
diff --git a/res/layout/calc_history_button.xml b/res/layout/calc_history_button.xml
new file mode 100644
index 00000000..ee4bacc1
--- /dev/null
+++ b/res/layout/calc_history_button.xml
@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+  ~ For more information, please, contact se.solovyev@gmail.com
+  ~ or visit http://se.solovyev.org
+  -->
+<org.solovyev.android.view.widgets.DirectionDragButton xmlns:a="http://schemas.android.com/apk/res/android"
+													   xmlns:calc="http://schemas.android.com/apk/res/org.solovyev.android.calculator"
+													   a:id="@+id/historyButton"
+													   a:text=""
+													   calc:textUp="@string/c_undo"
+													   calc:textDown="@string/c_redo"
+													   style="@style/control_button_style"/>
\ No newline at end of file
diff --git a/res/layout/calc_left_button.xml b/res/layout/calc_left_button.xml
new file mode 100644
index 00000000..b4b3d283
--- /dev/null
+++ b/res/layout/calc_left_button.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+  ~ For more information, please, contact se.solovyev@gmail.com
+  ~ or visit http://se.solovyev.org
+  -->
+
+<org.solovyev.android.view.widgets.DirectionDragButton xmlns:a="http://schemas.android.com/apk/res/android"
+													   xmlns:calc="http://schemas.android.com/apk/res/org.solovyev.android.calculator"
+													   a:id="@+id/leftButton"
+													   calc:textUp="↞"
+													   a:text="←"
+													   style="@style/control_button_style"
+													   a:onClick="moveLeftButtonClickHandler"/>
\ No newline at end of file
diff --git a/res/layout/calc_multiplication_button.xml b/res/layout/calc_multiplication_button.xml
new file mode 100644
index 00000000..2f098764
--- /dev/null
+++ b/res/layout/calc_multiplication_button.xml
@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+  ~ For more information, please, contact se.solovyev@gmail.com
+  ~ or visit http://se.solovyev.org
+  -->
+
+<org.solovyev.android.view.widgets.DirectionDragButton xmlns:a="http://schemas.android.com/apk/res/android"
+													   xmlns:calc="http://schemas.android.com/apk/res/org.solovyev.android.calculator"
+													   a:id="@+id/multiplicationButton"
+													   a:text="×"
+													   calc:textUp="^"
+													   calc:textDown="^2"
+													   style="@style/digit_button_style"
+													   a:onClick="digitButtonClickHandler"/>
\ No newline at end of file
diff --git a/res/layout/calc_nine_digit_button.xml b/res/layout/calc_nine_digit_button.xml
new file mode 100644
index 00000000..5551abe5
--- /dev/null
+++ b/res/layout/calc_nine_digit_button.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+  ~ For more information, please, contact se.solovyev@gmail.com
+  ~ or visit http://se.solovyev.org
+  -->
+
+<org.solovyev.android.view.widgets.DirectionDragButton xmlns:a="http://schemas.android.com/apk/res/android"
+													   xmlns:calc="http://schemas.android.com/apk/res/org.solovyev.android.calculator"
+													   a:id="@+id/nineDigitButton" a:text="9"
+													   calc:textDown="e"
+													   calc:textUp="π"
+													   style="@style/digit_button_style"
+													   a:onClick="digitButtonClickHandler"/>
\ No newline at end of file
diff --git a/res/layout/calc_one_digit_button.xml b/res/layout/calc_one_digit_button.xml
new file mode 100644
index 00000000..a8122356
--- /dev/null
+++ b/res/layout/calc_one_digit_button.xml
@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+  ~ For more information, please, contact se.solovyev@gmail.com
+  ~ or visit http://se.solovyev.org
+  -->
+
+<org.solovyev.android.view.widgets.DirectionDragButton xmlns:a="http://schemas.android.com/apk/res/android"
+													   xmlns:calc="http://schemas.android.com/apk/res/org.solovyev.android.calculator"
+													   a:id="@+id/oneDigitButton"
+													   a:text="1"
+													   calc:textUp="sin"
+													   calc:textDown="asin"
+													   style="@style/digit_button_style"
+													   a:onClick="digitButtonClickHandler"/>
\ No newline at end of file
diff --git a/res/layout/calc_paste_button.xml b/res/layout/calc_paste_button.xml
new file mode 100644
index 00000000..e2d73b8c
--- /dev/null
+++ b/res/layout/calc_paste_button.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+  ~ For more information, please, contact se.solovyev@gmail.com
+  ~ or visit http://se.solovyev.org
+  -->
+
+<ImageButton xmlns:a="http://schemas.android.com/apk/res/android"
+			 xmlns:calc="http://schemas.android.com/apk/res/org.solovyev.android.calculator"
+			 a:id="@+id/pasteButton"
+			 a:src="@drawable/paste"
+			 style="@style/control_button_style"
+			 a:padding="6dp"
+			 a:onClick="pasteButtonClickHandler"/>
\ No newline at end of file
diff --git a/res/layout/calc_plus_button.xml b/res/layout/calc_plus_button.xml
new file mode 100644
index 00000000..c0124cb7
--- /dev/null
+++ b/res/layout/calc_plus_button.xml
@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+  ~ For more information, please, contact se.solovyev@gmail.com
+  ~ or visit http://se.solovyev.org
+  -->
+<org.solovyev.android.view.widgets.DirectionDragButton xmlns:a="http://schemas.android.com/apk/res/android"
+													   xmlns:calc="http://schemas.android.com/apk/res/org.solovyev.android.calculator"
+													   a:id="@+id/plusButton" a:text="+"
+													   style="@style/digit_button_style"
+													   a:onClick="digitButtonClickHandler"/>
\ No newline at end of file
diff --git a/res/layout/calc_right_button.xml b/res/layout/calc_right_button.xml
new file mode 100644
index 00000000..a3166423
--- /dev/null
+++ b/res/layout/calc_right_button.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+  ~ For more information, please, contact se.solovyev@gmail.com
+  ~ or visit http://se.solovyev.org
+  -->
+
+<org.solovyev.android.view.widgets.DirectionDragButton xmlns:a="http://schemas.android.com/apk/res/android"
+													   xmlns:calc="http://schemas.android.com/apk/res/org.solovyev.android.calculator"
+													   a:id="@+id/rightButton"
+													   calc:textUp="↠"
+													   a:text="→"
+													   style="@style/control_button_style"
+													   a:onClick="moveRightButtonClickHandler"/>
\ No newline at end of file
diff --git a/res/layout/calc_round_brackets_button.xml b/res/layout/calc_round_brackets_button.xml
new file mode 100644
index 00000000..e721bedc
--- /dev/null
+++ b/res/layout/calc_round_brackets_button.xml
@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+  ~ For more information, please, contact se.solovyev@gmail.com
+  ~ or visit http://se.solovyev.org
+  -->
+
+<org.solovyev.android.view.widgets.DirectionDragButton xmlns:a="http://schemas.android.com/apk/res/android"
+													   xmlns:calc="http://schemas.android.com/apk/res/org.solovyev.android.calculator"
+													   a:id="@+id/roundBracketsButton" a:text="()"
+													   calc:textUp="("
+													   calc:textDown=")" style="@style/digit_button_style"
+													   a:onClick="digitButtonClickHandler"/>
\ No newline at end of file
diff --git a/res/layout/calc_seven_digit_button.xml b/res/layout/calc_seven_digit_button.xml
new file mode 100644
index 00000000..04813bc1
--- /dev/null
+++ b/res/layout/calc_seven_digit_button.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+  ~ For more information, please, contact se.solovyev@gmail.com
+  ~ or visit http://se.solovyev.org
+  -->
+
+<org.solovyev.android.view.widgets.DirectionDragButton xmlns:a="http://schemas.android.com/apk/res/android"
+													   xmlns:calc="http://schemas.android.com/apk/res/org.solovyev.android.calculator"
+													   a:id="@+id/sevenDigitButton" a:text="7"
+													   calc:textUp="i"
+													   calc:textDown=""
+													   style="@style/digit_button_style"
+													   a:onClick="digitButtonClickHandler"/>
\ No newline at end of file
diff --git a/res/layout/calc_six_digit_button.xml b/res/layout/calc_six_digit_button.xml
new file mode 100644
index 00000000..8246edb7
--- /dev/null
+++ b/res/layout/calc_six_digit_button.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+  ~ For more information, please, contact se.solovyev@gmail.com
+  ~ or visit http://se.solovyev.org
+  -->
+
+<org.solovyev.android.view.widgets.DirectionDragButton xmlns:a="http://schemas.android.com/apk/res/android"
+													   xmlns:calc="http://schemas.android.com/apk/res/org.solovyev.android.calculator"
+													   a:id="@+id/sixDigitButton" a:text="6"
+													   calc:textUp="tanh"
+													   calc:textDown="atanh"
+													   style="@style/digit_button_style"
+													   a:onClick="digitButtonClickHandler"/>
\ No newline at end of file
diff --git a/res/layout/calc_square_brackets_button.xml b/res/layout/calc_square_brackets_button.xml
new file mode 100644
index 00000000..360d83aa
--- /dev/null
+++ b/res/layout/calc_square_brackets_button.xml
@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+  ~ For more information, please, contact se.solovyev@gmail.com
+  ~ or visit http://se.solovyev.org
+  -->
+
+<org.solovyev.android.view.widgets.DirectionDragButton xmlns:a="http://schemas.android.com/apk/res/android"
+													   xmlns:calc="http://schemas.android.com/apk/res/org.solovyev.android.calculator"
+													   a:id="@+id/squareBracketsButton" a:text="[]"
+													   calc:textUp="["
+													   calc:textDown="]" style="@style/digit_button_style"
+													   a:onClick="digitButtonClickHandler"/>
\ No newline at end of file
diff --git a/res/layout/calc_subtraction_button.xml b/res/layout/calc_subtraction_button.xml
new file mode 100644
index 00000000..cc48a901
--- /dev/null
+++ b/res/layout/calc_subtraction_button.xml
@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+  ~ For more information, please, contact se.solovyev@gmail.com
+  ~ or visit http://se.solovyev.org
+  -->
+<org.solovyev.android.view.widgets.DirectionDragButton xmlns:a="http://schemas.android.com/apk/res/android"
+													   xmlns:calc="http://schemas.android.com/apk/res/org.solovyev.android.calculator"
+													   a:id="@+id/subtractionButton" a:text="-"
+													   calc:textUp="{"
+													   calc:textDown="}"
+													   style="@style/digit_button_style"
+													   a:onClick="digitButtonClickHandler"/>
\ No newline at end of file
diff --git a/res/layout/calc_three_digit_button.xml b/res/layout/calc_three_digit_button.xml
new file mode 100644
index 00000000..c35e6e78
--- /dev/null
+++ b/res/layout/calc_three_digit_button.xml
@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+  ~ For more information, please, contact se.solovyev@gmail.com
+  ~ or visit http://se.solovyev.org
+  -->
+
+<org.solovyev.android.view.widgets.DirectionDragButton xmlns:a="http://schemas.android.com/apk/res/android"
+													   xmlns:calc="http://schemas.android.com/apk/res/org.solovyev.android.calculator"
+													   a:id="@+id/threeDigitButton"
+													   a:text="3"
+													   calc:textUp="tan"
+													   calc:textDown="atan"
+													   style="@style/digit_button_style"
+													   a:onClick="digitButtonClickHandler"/>
\ No newline at end of file
diff --git a/res/layout/calc_two_digit_button.xml b/res/layout/calc_two_digit_button.xml
new file mode 100644
index 00000000..7df28622
--- /dev/null
+++ b/res/layout/calc_two_digit_button.xml
@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+  ~ For more information, please, contact se.solovyev@gmail.com
+  ~ or visit http://se.solovyev.org
+  -->
+
+<org.solovyev.android.view.widgets.DirectionDragButton xmlns:a="http://schemas.android.com/apk/res/android"
+													   xmlns:calc="http://schemas.android.com/apk/res/org.solovyev.android.calculator"
+													   a:id="@+id/twoDigitButton"
+													   a:text="2"
+													   calc:textUp="cos"
+													   calc:textDown="acos"
+													   style="@style/digit_button_style"
+													   a:onClick="digitButtonClickHandler"/>
\ No newline at end of file
diff --git a/res/layout/calc_vars_button.xml b/res/layout/calc_vars_button.xml
new file mode 100644
index 00000000..78efa2b0
--- /dev/null
+++ b/res/layout/calc_vars_button.xml
@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+  ~ For more information, please, contact se.solovyev@gmail.com
+  ~ or visit http://se.solovyev.org
+  -->
+
+<org.solovyev.android.view.widgets.DirectionDragButton xmlns:a="http://schemas.android.com/apk/res/android"
+													   a:id="@+id/varsButton"
+													   a:text="π,e,…"
+													   a:textStyle="italic"
+													   a:onClick="varsButtonClickHandler"
+													   style="@style/control_button_style"/>
\ No newline at end of file
diff --git a/res/layout/calc_zero_digit_button.xml b/res/layout/calc_zero_digit_button.xml
new file mode 100644
index 00000000..3bb1b7f7
--- /dev/null
+++ b/res/layout/calc_zero_digit_button.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<!--
+  ~ Copyright (c) 2009-2011. Created by serso aka se.solovyev.
+  ~ For more information, please, contact se.solovyev@gmail.com
+  ~ or visit http://se.solovyev.org
+  -->
+
+<org.solovyev.android.view.widgets.DirectionDragButton xmlns:a="http://schemas.android.com/apk/res/android"
+													   xmlns:calc="http://schemas.android.com/apk/res/org.solovyev.android.calculator"
+													   a:id="@+id/zeroDigitButton" a:text="0"
+													   calc:textUp="."
+													   calc:textDown=","
+													   style="@style/digit_button_style"
+													   a:onClick="digitButtonClickHandler"/>
\ No newline at end of file
diff --git a/res/values/strings.xml b/res/values/strings.xml
index 105168f3..e531f851 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -27,7 +27,8 @@
 
 	<string name="c_undo">undo</string>
 	<string name="c_redo">redo</string>
-	<string name="c_clear">clr</string>
+	<string name="c_clear">CE</string>
+	<string name="c_erase">C</string>
 	<string name="c_paste">paste</string>
 	<string name="c_vars">vars</string>
 
@@ -57,4 +58,5 @@
 	<string name="c_pi_description">Ratio of any circle\'s circumference to its diameter</string>
 	<string name="c_e_description">Unique real number such that the value of the derivative (slope of the tangent line) of the function f(x) = e^x at the point x = 0 is equal to 1</string>
 	<string name="c_i_description">Imaginary unit, defined such that i^2 = −1</string>
+	<string name="c_calc_editor_hint"></string>
 </resources>
diff --git a/res/values/styles.xml b/res/values/styles.xml
index a51fe817..a333480e 100644
--- a/res/values/styles.xml
+++ b/res/values/styles.xml
@@ -26,7 +26,7 @@
         <item name="android:textSize">30dp</item>
     </style>
 
-    <style name="display_style">
+	<style name="editor_style">
         <item name="android:textSize">25dp</item>
         <item name="android:background">#000000</item>
         <item name="android:textColor">@color/text_color</item>
@@ -36,4 +36,14 @@
         <item name="android:layout_height">match_parent</item>
     </style>
 
+    <style name="display_style">
+        <item name="android:textSize">25dp</item>
+        <item name="android:background">#000000</item>
+        <item name="android:textColor">@color/text_color</item>
+        <item name="android:gravity">right|center_vertical</item>
+		<item name="android:padding">5dp</item>
+        <item name="android:layout_width">match_parent</item>
+        <item name="android:layout_height">match_parent</item>
+    </style>
+
 </resources>
diff --git a/src/main/java/org/solovyev/android/calculator/CalculatorEditor.java b/src/main/java/org/solovyev/android/calculator/CalculatorEditor.java
index 468e4ec5..17b63185 100644
--- a/src/main/java/org/solovyev/android/calculator/CalculatorEditor.java
+++ b/src/main/java/org/solovyev/android/calculator/CalculatorEditor.java
@@ -23,6 +23,11 @@ public class CalculatorEditor extends EditText {
 
 	private boolean highlightText = true;
 
+	private final static int BASE_COLOUR = Color.WHITE;
+	private final static int BASE_COLOUR_RED_COMPONENT = Color.red(BASE_COLOUR);
+	private final static int BASE_COLOUR_GREEN_COMPONENT = Color.green(BASE_COLOUR);
+	private final static int BASE_COLOUR_BLUE_COMPONENT = Color.blue(BASE_COLOUR);
+
 	public CalculatorEditor(Context context) {
 		super(context);
 	}
@@ -135,13 +140,11 @@ public class CalculatorEditor extends EditText {
 	}
 
 	private String getColor(int numberOfOpenGroupSymbols, int numberOfOpenings) {
-		final int baseColor = Color.WHITE;
+		double c = 0.7;
 
-		double c = 1;
+		int offset = ((int) (255 * c)) * numberOfOpenings / (numberOfOpenGroupSymbols + 1);
 
-		int i = ((int) (255 * c)) * numberOfOpenings / (numberOfOpenGroupSymbols + 1);
-
-		int result = Color.rgb(Color.red(baseColor) - i, Color.green(baseColor) - i, Color.blue(baseColor) - i);
+		int result = Color.rgb(BASE_COLOUR_RED_COMPONENT - offset, BASE_COLOUR_GREEN_COMPONENT - offset, BASE_COLOUR_BLUE_COMPONENT - offset);
 
 		return "#" + Integer.toHexString(result).substring(2);
 	}
diff --git a/src/main/java/org/solovyev/android/calculator/CalculatorView.java b/src/main/java/org/solovyev/android/calculator/CalculatorView.java
index 1e96d7d1..8bb34d08 100644
--- a/src/main/java/org/solovyev/android/calculator/CalculatorView.java
+++ b/src/main/java/org/solovyev/android/calculator/CalculatorView.java
@@ -6,13 +6,10 @@
 package org.solovyev.android.calculator;
 
 import android.app.Activity;
-import android.content.Context;
 import android.os.Handler;
 import android.text.ClipboardManager;
-import android.text.InputType;
 import android.util.Log;
 import android.view.View;
-import android.view.inputmethod.InputMethodManager;
 import android.widget.EditText;
 import android.widget.TextView;
 import android.widget.Toast;
@@ -38,7 +35,7 @@ import org.solovyev.common.utils.history.SimpleHistoryHelper;
 public class CalculatorView implements CursorControl, HistoryControl<CalculatorHistoryState> {
 
 	// millis to wait before evaluation after user edit action
-	public static final int EVAL_DELAY_MILLIS = 700;
+	public static final int EVAL_DELAY_MILLIS = 1000;
 
 	@NotNull
 	private final CalculatorEditor editor;
@@ -55,11 +52,7 @@ public class CalculatorView implements CursorControl, HistoryControl<CalculatorH
 	public CalculatorView(@NotNull final Activity activity, @NotNull CalculatorModel calculator) {
 		this.calculatorModel = calculator;
 
-		final InputMethodManager imm = (InputMethodManager) activity.getSystemService(Context.INPUT_METHOD_SERVICE);
-
 		this.editor = (CalculatorEditor) activity.findViewById(R.id.editText);
-		this.editor.setInputType(InputType.TYPE_NULL);
-		imm.hideSoftInputFromWindow(this.editor.getWindowToken(), 0);
 
 		this.display = (CalculatorDisplay) activity.findViewById(R.id.resultEditText);
 		this.display.setOnClickListener(new View.OnClickListener() {
diff --git a/src/test/java/org/solovyev/android/calculator/model/CalculatorModelTest.java b/src/test/java/org/solovyev/android/calculator/model/CalculatorModelTest.java
index a069cc51..5cd55a20 100644
--- a/src/test/java/org/solovyev/android/calculator/model/CalculatorModelTest.java
+++ b/src/test/java/org/solovyev/android/calculator/model/CalculatorModelTest.java
@@ -9,6 +9,7 @@ import bsh.EvalError;
 import org.junit.Assert;
 import org.junit.BeforeClass;
 import org.junit.Test;
+import org.simpleframework.xml.Attribute;
 import org.solovyev.android.calculator.JsclOperation;
 
 /**
@@ -79,4 +80,50 @@ public class CalculatorModelTest {
 		Assert.assertEquals("i", cm.createResultForComplexNumber("i"));
 
 	}
+
+	public interface TestInterface {
+		Integer getField();
+	}
+
+	public class TestClass implements TestInterface{
+
+		@Attribute(required = true)
+		private Integer field;
+
+		public TestClass() {
+		}
+
+		public TestClass(Integer field) {
+			this.field = field;
+		}
+
+		public Integer getField() {
+			return field;
+		}
+
+		public void setField(Integer field) {
+			this.field = field;
+		}
+	}
+
+	public class NewTestClass implements TestInterface{
+
+		@Attribute
+		private Integer field;
+
+		public NewTestClass() {
+		}
+
+		public NewTestClass(Integer field) {
+			this.field = field;
+		}
+
+		public Integer getField() {
+			return field;
+		}
+
+		public void setField(Integer field) {
+			this.field = field;
+		}
+	}
 }